The United States and Japan will step up their defence cooperation to deal with the threat from nuclear-armed North Korea as tensions in East Asia remain high, officials from the two allies said on Thursday.

PM signs MH17 condolence book

Families of Australians killed in the MH17 disaster will be sent official condolence messages from the prime minister and his cabinet.

Prime Minister Tony Abbott signed a condolence book for the victims on behalf of the whole country on Tuesday.

"Twenty-three million Australians share the sadness of those who mourn," he wrote.

Governor-General Peter Cosgrove, Speaker Bronwyn Bishop, Senate president Stephen Parry, most cabinet ministers, military chiefs and ambassadors from all the countries affected by the crash also signed during the ceremony at Parliament House in Canberra.

"In our heart is pain, in our mind is a determination to see justice done," Mrs Bishop said.

The world had made it clear it would not tolerate such an act of brutality, she said.

About 200 school children and other visitors to Parliament House joined in a minute's silence before defence force Anglican Bishop Ian Lambert led the Lord's Prayer.